1. Field of the Invention
The present invention relates to a matrix electrode-controlling device and a digital platform using the same, and more particularly, to a matrix electrode-controlling device for driving a droplet and a digital platform for assaying a fluid using the same.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98
Controlling a droplet under test is an important technique for the biomedical assaying operation. To date, electrowetting is used as the conventional technique, which uses top and bottom electrodes in a sandwich structure to control the movement of the droplet, as disclosed in U.S. Pat. No. 6,565,727. However, the conventional technical faces a technical problem in that the droplet is restricted in space between the top and the bottom electrodes such that adding extra additives into the droplet under test from the top side or the bottom side of the droplet during an assaying process is quite difficult. In addition, the conventional technique does not possess the ability of controlling the movements of multiple droplets simultaneously, and therefore the conventional technique is restricted from being applied to the processes of assaying samples such as genes or protein chips.
Chip design using the electrowetting effect to drive the droplet generally use the following two methods to apply a predetermined voltage to the control electrodes:
Method 1: assigning connecting wires to each control electrode, and applying voltage to the desired control electrode to generate the electrowetting effect by directly applying the voltage to the desired control electrode via the assigned connecting wire (see: Pollack, M. G., Fair, R. B., and Shenderov, A. D., Electrowetting-based actuation of liquid droplets for microfluidic applications, Appl. Phys. Lett. 77 (2000) 1725-1726).
Method 2: using the opto-electrowetting (OEW) technique, in which connecting wires connecting the control electrodes are biased to a predetermined voltage in advance, and an optically sensitive material is positioned between the control electrodes and the connecting wires such that the control electrode is not biased to the predetermined voltage. A laser light irradiates on the optical sensitive material to bias the predetermined voltage to certain control electrodes to generate the driving force (see: Chiou, P. Y., Chang, Z., and Wu, M. C., Light actuated microfluidic devices, MEMS-03 (2003) 355-358).
Method 1 is a direct design, but requires a number of connecting wires to connect each control electrode to the power supply, and the circuit layer is quite complicated for a design with a large number of control electrodes. Method 2 solves the complicated circuit layout problem, but needs additional laser sources, which make the entire system very large.
To solve the above problems, researchers try to incorporate Method 1 and Method 2 to achieve two-dimensional driving ability of the droplet (see: Fan, S. K., Hashi, C., and Kim, C. J., Manipulation of multiple droplet on N×M grid by cross-reference EWOD driving scheme and pressure-contact package, MEMS-03 (2003) 694-697). Nevertheless, this technique also faces the same problem as Method 1 and Method 2 due to use of the electrowetting on dielectric (EWOD) design, i.e., the top and bottom electrodes in the sandwich structure restrict the space for adding extra additives.
The inventor of the present invention recognizes the above issue and provides a matrix electrode-controlling device using a single side electrode architecture to reduce the required space such that both the complicated circuit layout problem for a design with a large number of control electrodes and the huge system issue can be resolved, and some possible new applications can be created.